PUBLIC HEALTH ASSESSMENT
PALMERTON ZINC PILE
PALMERTON, CARBON COUNTY, PENNSYLVANIA
Contaminants of concern are identified in this section of the document. We evaluate these contaminants in the subsequent sections of the public health assessment and determine whether exposure to them has public health significance. A listed contaminant does not mean that exposure to it will cause adverse health effects. Instead, the list indicates which contaminants will be evaluated further in the public health assessment. Comparison values for public health assessments are contaminant concentrations in specific media that are used to select contaminants for further evaluation. These values include Environmental Media Evaluation Guides (EMEGs) and Reference Dose Media Environmental Guides (RMEGs). If environmental media guides cannot be established because of a lack of available health data, other comparison values may be used to select a contaminant for further evaluation.
We conducted a search of the EPA Toxic Chemical Release Inventory (TRI) for the site and local area. TRI contains information on estimated annual releases of toxic chemicals to the environment (via air, water, soil, or underground injection) which is reported by companies to EPA. TRI data can be used to give a general idea of the current environmental emissions occurring at a site and in the area surrounding a site. TRI data may also be used to determine whether the on-going emissions from reporting facilities may be contributing an additional exposure to the nearby population. No other facilities in the area listed releases of related contaminants to the environment.
Only off-site contamination is addressed in this section because the focus of this public health assessment is on Operable Unit #3, the off-site soil contamination. However, pertinent information available for some other off-site environmental media is included in this section. Additionally, data for different environmental media have been collected since the beginning of the public health assessment process. That information will be evaluated, and results will be recorded through other processes such as site review and update documents.
EPA's designated Operable Unit #3 of the Palmerton Zinc Pile site is the off-site contamination of the valley surrounding the two plants. Soil samples were collected in two phases. Phase 1 samples were collected from October to December 1985, and Phase 2 samples were collected during June and July 1986. Soil samples were analyzed by the Pennsylvania State University Soil and Environmental Chemistry Laboratory.
The first soil sampling phase concentrated on locations in Palmerton and along eight transects radiating from Palmerton. The direction and length of these transects were determined, in part, by wind direction and topography, with the longest transects trending northeast and southeast. The second sampling phase was conducted in order to verify and better delineate Phase 1 results. Locations for the Phase 2 sampling were concentrated in outlying areas of Palmerton, primarily to the north (4).
Phase 1 soil sampling encompassed 207 locations and consisted of compositing four subsamples that were collected from the top 30 centimeters (cm) of soil. Phase 2 soil sampling involved an additional 217 locations, which were selected to better delineate the extent and severity of contamination identified during the Phase 1 investigation. Phase 2 samples consisted of nine composited subsamples, all collected from the top 15 cm of soil. Table 1 provides information on contaminants of concern for Phase 1 and Phase 2 sampling rounds. Please refer to Appendix B for tables on the 1991 sampling results for soils and indoor dust. That information is evaluated in the health consultation, Appendix B.
Maximum Soil Concentrations (mg/kg)(a)
|CONTAMINANT||PHASE 1||PHASE 2||COMPARISON VALUE|
|(a)||From EPA's analysis summary - NOTE: because of minor differences
in reported minimums throughout the RI and listed in RI appendices, minimums
are not listed here.
|Copper analyses were conducted only in Phase 1 sampling because
the contractor determined that copper concentrations were not at levels
|Madhaven et al (1989). The 250 mg/kg value applies to a worst-case scenario for young children with frequent mouthing habits; the value is believed to add, at most, an estimated 2 µg/dL to the blood lead of the child.|
Analyses of the two phases of soil sampling (a total of 413 samples) in and around Palmerton were evaluated by EPA. EPA's Environmental Research Center concluded that metal (lead, cadmium, and zinc) concentrations in soils are highest between and at the edges of the two smelter locations, along the Aquashicola Creek valley (east-northeast) between Blue Mountain and Stoney Ridge, and in the Lehigh River Gap area (2). Isopleth maps (contours representing equal concentrations of heavy metals in soils) for these three metals were developed (see Figures 2, 3, 4). In addition, analyses of concentrations of heavy metals in soils at various soil depths were conducted. These analyses showed that cadmium and lead concentrations decrease below 7.5 cm in depth, and even lower concentrations of metals are found at depths to 15 cm; therefore, contamination is basically in the top 6 inches of soil, a depth at which people may come into contact with contaminants, although the top 3 inches is of most concern (4). It is evident from the isopleths that the concentrations of cadmium and zinc decrease with distance from the Plants.
Soil and indoor dust samples were collected and analyzed for lead, cadmium, zinc, and arsenic in 1991. That data are presented and discussed in the health consultation, Appendix B, of this document. High levels of these metals were found in indoor dust and porch dust, but all possible sources for the contamination were not determined. Arsenic, in addition to the other contaminants of concern, was found at levels that exceed comparison values in soil and dust.
Some drinking water supplies, drawn from area groundwater, contain lead, cadmium, and arsenic at levels that exceed comparison values. In a 1985 health consultation prepared by ATSDR, levels of lead and cadmium were found in well water samples at 20-3,200 µg/L and 2-24 µg/L, respectively. The document was not clear as to whether or not the wells with highest concentrations of the metals were ever used as drinking water. Area tap water was tested in 1991. Those results are discussed in the 1991 health consultation (Appendix B).
Cadmium, lead, and zinc were evaluated for their potential to accumulate in animals, including fish, and in vegetables that may be consumed by people in the area.
As part of the RI, a garden vegetable/cadmium uptake study was conducted in 1987 by Pennsylvania State University. Soil treatments were part of the study. The conclusions listed in the study included: soils contaminated with high levels of zinc will not support growth of the plants; and people eating all home-grown vegetables would increase their dietary cadmium intake by 35 to 50 µg/day (4).
An independent assessment on wildlife impact in the area was completed in 1989 for the U.S. Fish and Wildlife Service. The conclusions included that the number of amphibian species, bird species, and small mammals increased with distance from the site. Also, disease in mammals was greatest adjacent to site. The heavy metal concentrations, particularly in deer liver and kidney, decreased with distance from the site, and the metal levels found in deer adjacent to the site were about five times that of a control population (9).
Another independent study on the effects of area contamination on aquatic fauna in the vicinity of Palmerton was conducted for the U.S. Fish and Wildlife Service in 1988. The study was designed to assess impact through measuring species number and diversity and not through measuring actual levels of contaminants that may be present in aquatic animals. The report concluded that only those fish and insect populations adjacent and downstream of the cinder pile were adversely impacted (10).
Fish were collected and analyzed for lead and cadmium by the U.S. Fish and Wildlife Service in 1985. Lead was found in fish at concentrations greater than 2 µg/kg, and cadmium was found in fish at concentrations greater than 0.45 µg/kg. The species of fish tested and exact levels of contaminants detected were not provided in the documents reviewed. The data were evaluated by ATSDR in 1987. ATSDR concluded, at that time, fish from streams in the immediate area of Blue Mountain should not be consumed more than once a week in order to avoid possible adverse health effects that may result because of consumption of the contaminated fish tissue (5).
In preparing this public health assessment, PADOH relies on the information provided in the RI and assumes that adequate quality assurance and quality control measures were followed in the RI regarding chain-of-custody, laboratory procedures, and data reporting. The validity of the analyses and conclusions drawn for this public health assessment are determined by the availability and reliability of the referenced information.
Soil sampling studies conducted prior to the RI investigation were not as extensive as the soil sampling activities of the RI nor did they have adequate quality assurance/quality control safeguards. Trying to compare soil samples from previous studies to current results is difficult because of varying sample locations and depths, different sampling methods, and other variables.
There are no known physical hazards associated with the site.
To determine whether residents are exposed to contaminants migrating from the site, PADOH and ATSDR evaluate the environmental and human components that lead to human exposure. An exposure pathway consists of five elements: a source of contamination, transport through an environmental medium, a point of exposure, a route of human exposure, and a receptor population.
PADOH and ATSDR identify exposure pathways as completed, potential, or eliminated. In completed exposure pathways, all five elements exist and exposure to a contaminant has occurred in the past, is occurring, or will occur in the future. In potential exposure pathways, however, at least one of the five elements is missing, but could exist. Potential exposure pathways indicate that exposure to a contaminant could have occurred in the past, could be occurring now, or could occur in the future. In eliminated exposure pathways, at least one of the five elements is missing and will never be present.
Although Operable Unit #3 focuses on arsenic, lead, cadmium, and zinc soil contamination throughout the valley, the contaminated soil serves as a continuing source of contamination to the air, surface water, groundwater, sediments, and local foods (fish, garden vegetables, and game meats). All exposure pathways are evaluated in this section.
Palmerton is located within the 100-150 ppm concentration isopleth for cadmium, the 250-500 ppm isopleth for lead, with some isolated areas at levels over 500 ppm, and the 2,500-10,000 ppm isopleth for zinc (4). The highest levels of cadmium and lead were found on the north slope of Blue Mountain near Lehigh Gap. Cadmium levels in that area exceed 200 ppm, and lead levels exceed 1,000 ppm. The highest zinc level, which was 40,000 ppm, was found north of the Lehigh Gap on the shore of the Lehigh River, but high levels of zinc were also found on the north slope of Blue Mountain. The Aquashicola area, southwest of the East Plant, also has high levels of lead in soils. Indoor and porch dust samples collected in 1991 contained even higher levels of cadmium than found in outdoor soils, and lead concentrations were highest in porch dust. Samples collected in 1991 were also analyzed for arsenic. Arsenic is present in soils and indoor dust at levels exceeding comparison values. The highest concentrations were found in indoor dust. Other possible sources of the contamination, especially for indoor dust levels, have not been conclusively identified.
People who live and work in the study area come into contact with contaminated soil as they walk, play, or work in their yards and recreational areas. People also track contaminated soil into their homes when they walk through unvegetated areas. Additionally, wind blown particles enter homes and businesses; therefore, people are exposed to soil contaminants when they are inside buildings as well as outside. Young children are of most concern because their play habits result in ingestion of more soil than adults would be expected to ingest through their activities. An estimated 6,000 people are thought to be exposed to contaminated soils. They are exposed through incidental ingestion of the contaminated soil and inhalation and ingestion of airborne particulates (contaminated dust particles).
Drinking water is known to contain lead, cadmium, and arsenic at levels exceeding comparison values. Tap water samples collected after flushing lines for 30 minuets (see Appendix B) contained a maximum cadmium level of 11.7 ppb, a maximum lead level of 43.3 ppb, and a maximum arsenic level of 10 ppb. The number of people drinking water that contains cadmium and lead at levels above comparison values is unclear. The population studied will be better defined in the Biological Indicators of Exposure to Cadmium and Lead, Palmerton, Pennsylvania study scheduled for release in 1994. People ingest the contaminated water when it is used for drinking and cooking.
Cadmium and lead have low water solubility. They tend to absorb onto the soil particles, which limits the migration of the contaminants to some extent. The metals can accumulate in animals and fish, however, and are taken up by garden vegetables. The metals in the soil may be taken up by plants and ingested by animals. The animals can then incorporate the metals into their bodies. Fish accumulate metals in their bodies through ingesting or breathing contaminants that are present in the surface water and ingesting contaminants present in sediments and their food. Several studies conducted in the past, as well as current studies, indicate that vegetables, game animals, and fish contain contaminants (3). People who consume contaminated vegetables, fish, and land animals also consume the contaminants present in the food. About 900 families have gardens. However, information is lacking on how much those people eat. Also, information is lacking on the number of people who consume fish and other animals and how much they eat.
Surface waters are contaminated (see Background section). No data were reviewed for this document on recent levels of contamination other than to identify the area of Aquashicola Creek located near the cinder bank of the East Plant as containing high levels of the contaminants of concern. People who use surface water for recreational purposes could be exposed to contaminants in the water through incidental ingestion.
Past exposure to air emissions from stack operations are likely to have occurred.
However, air data are not available to assess likely past exposures. Exposure
to airborne particulates is discussed under Soils
in the Completed Exposure Pathways section.
In this section, we discuss the health effects that may occur in persons exposed to site contaminants, evaluate the relevance of state health data bases to provide information for the site, and evaluate community health concerns.
In evaluating health effects, several factors determine whether harmful effects will occur and the type and severity of those health effects. These factors include the dose (how much), the duration (how long), the route by which people are exposed (breathing, eating, drinking, or skin contact), the other contaminants to which they may be exposed, and their individual characteristics such as age, sex, nutrition, family traits, life style, and state of health. The scientific discipline that evaluates these factors and the potential for a chemical exposure to adversely impact health is called toxicology.
In order to determine whether adverse health effects are possible as a result of exposure to a contaminant, an exposure dose must be estimated for each pathway. This exposure dose can then be compared with appropriate toxicity values in order to evaluate the likelihood of adverse health effects occurring. Toxicity values used to evaluate noncancer adverse health effects include ATSDR's Minimal Risk Level (MRL) and EPA's Reference Dose (RfD) for ingestion and Reference Concentration (RfC) for inhalation. The MRL, RfD, or RfC values are estimates of daily human exposure to a contaminant below which non-cancer, adverse health effects are unlikely to occur.
The National Toxicology Program (NTP), the International Agency for Research on Cancer (IARC), and EPA have reviewed available information from human and/or animal studies to determine whether certain chemicals are likely to cause cancer in humans. The potential for cancer to occur in an individual or a population is evaluated by estimating the probability of an individual developing cancer over a lifetime as the result of the exposure. EPA has developed cancer slope factors for many carcinogens. A cancer slope factor is an estimate of a chemical's potential for causing cancer. If adequate information about the level of exposure, frequency of exposure, and length of exposure to a particular carcinogen is available, an estimate of excess cancer risk associated with the exposure can be calculated using the cancer slope factor for that carcinogen.
Cancer risk is the likelihood, or chance, of getting cancer. We say "excess cancer risk" because we have a "background risk" of about one in four chances of getting cancer from all other causes. In other words, in a million people, it is expected that 250,000 would get cancer from a variety of causes. If we say there is a "one-in-a-million" excess cancer risk from a given exposure to a contaminant, we mean that if one million persons are exposed to a carcinogen at a certain level over their lifetime, then one cancer above the background chance, or the "250,001st" cancer, may appear in those million persons from that particular exposure. In order to take into account the uncertainties in the science, the risk numbers used are plausible upper limits of the actual risk based on conservative assumptions. In actuality, the risk is probably somewhat lower than that calculated, and in fact, may be zero.
The contaminants of concern at the site are arsenic, cadmium, lead, and zinc. People in the study area have been exposed to those metals. Exposure is, primarily, through contact with contaminated soils; however, people have also been exposed to the metals in their drinking water. Other possible exposure pathways have been identified (through food ingestion, contact with contaminated surface water, and through inhalation of contaminated air). Only known exposures are evaluated in this section.
People in the study area of the Palmerton Zinc Pile site have been exposed to arsenic in soils and in drinking water. The people are exposed to arsenic through incidental ingestion of contaminated soil (and household dust) and ingestion and inhalation of airborne particulates. People who use water contaminated with arsenic are also exposed to the arsenic through ingestion of the water.
The highest levels of arsenic in soil were found in indoor dust in the 1991 sampling study. The maximum level found was 503 ppm. By using maximum concentrations, worst-case conditions will be addressed. ATSDR has established a chronic (long-term exposure) MRL for arsenic (18). The estimated dose for people exposed to those levels of arsenic in soil (dust) exceeds the chronic MRL. Additionally, some people are exposed to arsenic in their drinking water. The highest level of arsenic found in 1991 tap water samples was 10 ppb. The maximum level of arsenic in tap water approaches a dose for adults that equals the MRL, and the estimated dose for a child exceeds the MRL. Adults, as well as children, exposed to the contaminated tap water may also be exposed to arsenic in soil, thereby increasing the actual dose. Both adults and children exposed to the maximum levels of arsenic in soil (dust) and water over a long period of time may develop non-cancer adverse health effects (18).
Most arsenic enters the body by ingestion of food or water, although it may also be inhaled. Absorption through the skin is not usually an important pathway. Depending on its chemical form, arsenic quickly enters the bloodstream as it is absorbed by the stomach, intestines, and lungs. At low to moderate levels, arsenic does not accumulate in the body because it can be converted by the liver to a less toxic form that is easily excreted in the urine (18).
Exposure to arsenic may produce injury to a number of different body tissues. The common effect from ingesting arsenic is stomach irritation, pain, nausea, vomiting, and diarrhea. Prolonged exposure may cause decreased production of red and white blood cells, abnormal heart function, liver or kidney damage, and impaired nerve function. The most characteristic effect of arsenic exposure is a pattern of skin abnormalities including the appearance of dark and light spots on the skin, and small corns on the palms, soles, and trunk (18). Some of these abnormalities may lead to skin cancer.
There are very few studies on possible developmental effects associated with breathing arsenic. One study found that Swedish women who lived near or worked in a smelter had a higher rate of spontaneous abortions and produced babies with lower birth weights than expected (19). However, there was no excess in congenital malformations in the babies born to these exposed women (19). A limitation of this study is that it is not possible to definitively single out arsenic as the cause of abortions and low birth weights because the smelter produced a number of airborne pollutants, only one of which was arsenic.
EPA classifies arsenic as a known human carcinogen in humans exposed through the oral or inhalation routes. A cancer slope factor has been developed for arsenic (18). People exposed to maximum soil and drinking water levels are at a moderate increased risk of developing cancer.
People in the study area of the Palmerton Zinc Pile site have been exposed to cadmium in soils and in drinking water. The people are exposed to cadmium through incidental ingestion of contaminated soil and ingestion and inhalation of airborne particulates. People who use water contaminated with cadmium are also exposed to the cadmium through ingestion of the water.
The highest levels of cadmium in soil were found in indoor dust in the 1991 sampling study. The maximum level found was 2,501 ppm. By using maximum concentrations, worst-case conditions will be addressed. ATSDR has established a chronic (long-term exposure) MRL for cadmium (12). The estimated dose for people exposed to those levels of cadmium in soil (dust) exceeds the chronic MRL. Additionally, some people are exposed to cadmium in their drinking water. The highest levels of cadmium found in 1991 tap water samples was 11.7 ppb. Although the maximum level of cadmium in tap water would not result in a dose for adults that exceeds the MRL, the estimated dose for a child does exceed the MRL. Adults, as well as children, exposed to the contaminated tap water may also be exposed to cadmium in soil, thereby increasing the actual dose. Both adults and children exposed to the maximum levels of cadmium in soil (dust) over a long period of time may develop non-cancer adverse health effects. Exposure to high levels of cadmium has led to kidney and lung damage in people (12). These health effects were the result of ingestion of cadmium through the diet and inhalation of cadmium in manufacturing scenarios. High blood pressure has been observed in animals exposed to cadmium. A number of reports reveal that the toxicity of cadmium is influenced by the presence of dietary levels of other trace metals. Dietary deficiencies of metals (including zinc, iron, copper, selenium, and calcium) have been shown to increase the toxicity of cadmium (12). Conversely, an increased dietary intake of these metals has been reported to reduce or prevent cadmium-related health effects. Of concern in the Palmerton area are the health effects, particularly on the kidney, that may occur following long-term, low-level exposure (12).
EPA classifies cadmium as a probable human carcinogen. Studies in humans suggest that long-term inhalation of cadmium can result in an increased risk of developing lung cancer (12). However, no cancer slope factors have been developed for cadmium to evaluate the possible cancer risk for people living in the Palmerton area.
People in the study area of the Palmerton Zinc Pile site have been exposed to lead in soils and in drinking water. The people are exposed to lead through incidental ingestion of contaminated soil and ingestion and inhalation of airborne particulates. People who use water contaminated with lead are also exposed to the lead through ingestion of the water.
The highest levels of lead in soil were found in porch dust in the 1991 sampling study. The maximum level found was 17,700 ppm. The highest level found in tap water in the 1991 study was 43.3 ppb. ATSDR has not established a MRL for lead, nor has EPA established a RfD (13). The maximum concentration of lead in tap water does exceed EPA's Action Level of 15 ppb.
Lead primarily effects the peripheral and central nervous systems, the blood cells, and metabolism of vitamin D. Lead also causes reproductive toxicity. The most sensitive target of lead poisoning is the nervous system. In children, neurologic deficits have been documented at exposure levels once thought to cause no harmful effects. Neurologic deficits, as well as other effects caused by lead poisoning, may be irreversible. Effects in children generally occur at lower blood levels than adults (13).
The developing nervous system in children can be affected adversely at blood lead levels of as low as 10 micrograms per deciliter (µg/dL). Lead inhibits several enzymes that are critical to the synthesis of heme; however, lead poisoning in children rarely results in anemia. Lead also interferes with a hormonal form of vitamin D, which affects multiple processes in the body, including cell maturation and skeletal growth. Furthermore, maternal lead stores readily cross the placenta, placing the fetus at greatest risk (13).
Some persons with lead poisoning may not be overly symptomatic. Because of the differences in individual susceptibility, symptoms of lead intoxication and their onset may vary. With increasing exposure, the severity of symptoms can be expected to increase. In the early stages of symptomatic lead intoxication or mild toxicity, blood lead levels generally range from 35 to 50 µg/dL in children and 40 to 60 µg/dL in adults. Mild toxicity may result in muscle pain, irritability, and mild pain. Moderate toxicity may result in bone pain, general fatigue, difficulty concentrating, headache, diffuse abdominal pain, and weight loss. Severe lead toxicity may result in encephalopathy which may lead to seizures. A purplish line on the gums, known as a lead line, is rarely seen today, but if present, usually indicates severe and prolonged lead poisoning (13).
A blood lead level is the most useful screening and diagnostic test for lead poisoning (13). Current blood lead data for sensitive populations and for other persons known to be exposed to lead in soil and drinking water are not available at this time, but will be addressed in the health study that is to be released in 1994. Therefore, human exposure to lead and the corresponding non-cancer health effects associated with elevated blood lead levels cannot be addressed in this document.
EPA classifies lead as a probable human carcinogen. No cancer slope factor has been developed for lead to evaluate possible cancer risks to people exposed to lead in the study area (13).
People in the study area of the Palmerton Zinc Pile site have been exposed to zinc in soils at levels that exceed comparison values. The people are exposed to lead through incidental ingestion of contaminated soil and ingestion and inhalation of airborne particulates. Zinc is present in drinking water at levels below comparison values, but the zinc in the water may act as an additional source of zinc exposure to people exposed through other environmental media.
The highest levels of zinc in soil were found in street dust in the 1991 sampling study. The maximum level found was 94,200 ppm. ATSDR has not established a MRL for zinc, but EPA has established a RfD (11). However, the RfD is very conservative and approaches the Recommended Dietary Allowance (RDA) (11). An adult's estimated dose from exposure to that level of zinc does not exceed the RfD; however, a child's estimated dose from exposure to that level does exceed the RfD. Children, primarily pica children (those children who eat large amounts of non-food materials), exposed to the maximum levels of zinc in the area may experience non-cancer adverse health effects if consumption of zinc-contaminated soil is high enough to exceed normal dietary intake.
Zinc is a nutritionally essential metal for humans. Deficiencies of this metal can cause severe adverse health effects. Excessive exposure to zinc is relatively uncommon in non-occupational settings. Zinc does not bioaccumulate in humans, even after prolonged exposures. The average American daily intake is approximately 12 to 25 mg, most of which comes from food. The National Academy of Sciences established the RDA for zinc at 15 mg/day for men and 12 mg/day for women (11).
Eating very large amounts of zinc (10 to 15 times more than the RDA) may cause stomach cramps, nausea, and vomiting. Eating high levels of zinc for several months can decrease the levels of high-density lipoprotein cholesterol, cause anemia, and damage the pancreas (11).
EPA has determined that zinc is not classifiable as to its human carcinogenicity. No reliable human carcinogenicity data are available (11).
When evaluating health outcome data, some limitations apply. No statistical methods available to evaluate existing health outcome data are designed to discern subtle features that may be present in small populations. For that reason, some adverse health effects that may occur in exposed individuals may not be found as statistically significant. In reality, we have no way of showing a cause/effect pattern with these statistical methods. We can, however, sometimes show trends that may warrant more specific studies. For that reason, we feel these evaluations are appropriate for purposes of public health assessments.
- Death certificate evaluation at Palmerton Hospital was done as part of
the RI Risk Assessment for 1,815 deaths over a 22-year period. The author
summarized his study as "no significant difference between the patients living
in the Palmerton area and those from other communities." A second opinion
from a physician was requested to re-evaluate the data, and he concluded that
the data indicate an increase in cirrhosis in the under 70 age group, and
an increase in prostate cancer in the over 70 age group. However, neither
disease can be directly linked to cadmium exposure (4).
- ATSDR's (1985) mortality analysis from 1950-1979 basically states that
the only cancer mortality rate that is consistently elevated in most counties
involved is for rectal cancer. However, the mortality rate for this type of
cancer is also elevated for the State of Pennsylvania and, thus, may not be
associated with the site (7).
- PADOH collected twenty years of data for mortality (all causes) and cancer
mortality (total cancer and eight organ cancer sites) collected for Palmerton
The 1979-1989 data were analyzed using the Pennsylvania 1979-1981 mortality experience as a standard, and the 1980 Census population for age and sex. This analysis indicated fewer observed deaths (all causes) than expected for the 11-year period. There were 801 deaths observed with 832.4 deaths expected for a Standard Mortality Ratio (SMR) of 0.962. This difference is not statistically significant.
Total cancer mortality analysis also indicated fewer total cancer deaths than expected for the 1979-1989 period. There were 170 observed cancer deaths and 177.5 expected for an SMR of 0.958. (An "expected" death is a statistical term used for measuring mortality among a specified population. In this case, the age-sex specific death rates by 5 year age groups for a selected cause of death for Pennsylvania is applied to the same age-sex population in Palmerton Borough to obtain an "expected" number of deaths. This tells the investigator how many deaths one would expect to see in Palmerton Borough if the mortality experience was the same as in the standard population - Pennsylvania. This is known as the indirect method of mortality adjustment.) This difference again is not statistically significant. The eight cancer sites available for analyses for Palmerton Borough were as follows: (1) buccal cavity and pharynx; (2) digestive system; (3) respiratory system; (4) bone, connective tissue, skin, and breast; (5) genitourinary system; (6) other and unspecified sites; (7) leukemia; and (8) other lymphatic and hematopoietic tissues.
There were no statistically significant Standard Mortality Ratios (SMRs) in any of the eight cancer categories with the exception of cancer of other lymphatic and hematopoietic tissues. This cancer category was statistically significantly with 16 observed deaths and 8.7 deaths expected, producing an SMR of 1.839. This is statistically significant by a factor of one death over the 11-year period. Such differences are typical in small area investigations. Five of the eight investigated cancer sites had SMRs below unity.
The mortality analysis for all causes of death and total cancer indicated less mortality than expected when compared to the standard population of Pennsylvania. However, this type of analysis provides a surveillance tool for comparing mortality in populations. This type of analysis is not able to address adverse health effects that may be seen in the living population.
- The Palmerton Hospital's voluntary blood lead testing program that was conducted
in the spring of 1991 cannot be analyzed as though it were a community epidemiological
study because it was a voluntary program (15).
Because of the voluntary nature of the program, results may be misleading
because all people tested may not be from the study area, and a large number
of people affected may not be tested. No conclusions can be drawn about the
tests under those circumstances. However, the tests helped identify people
who may have had high blood lead levels.
- A case-control study by the National Cancer Institute was conducted in 1980-1981
in the vicinity of Palmerton to investigate the role of environmental pollutants
on the etiology of lung cancer. A two-fold risk for developing lung cancer
was associated with residence near the smelter, although the number of individuals
living in these higher risk areas was small. The study concluded that no causal
interpretation could be made, but the need for further studies was indicated
- The National Institute for Occupational Safety and Health conducted a Health
Hazard Evaluation at the Carbonnaire Company in Palmerton in 1991. The conclusions
in that report, relative to lead, indicated that soil samples and dust samples
from the furnace filters were contaminated with lead. The air sampling and
blood analyses did not indicate that people were excessively exposed to lead.
Because of the close proximity of the Carbonnaire Company to the Palmerton
Zinc Pile site, it was also concluded that the potential lead exposure is
apparently from the dust in the air settling in the soil coming from the Palmerton
Zinc Pile site (17).
- EPA asked ATSDR to evaluate public health threats posed by exposures to
metals detected in areas surrounding the Palmerton Zinc Pile site. In addition
to a health consultation, EPA requested comments on the proposed removal response
action levels in residential surface soil and dust within homes where children
up to 6 years old and pregnant women reside. Among the consult's conclusions
were that the levels of lead, cadmium, zinc, and arsenic detected in the Palmerton
area samples may pose a health threat, particularly to young children. EPA's
removal action levels of both 1,500 mg lead/kg and 100 mg cadmium/kg residential
soil or interior dust may not be protective of the health of children and
pregnant women (see Appendix B).
- A comprehensive study Biological Indicators of Exposure to Cadmium and Lead, Palmerton, Pennsylvania has been completed and the findings will be released in 1994 in two parts. The first part should provide answers to the following study objectives:
- To determine the dose measures of cadmium and lead in blood and urine in the target population (Palmerton and part of Aquashicola) and compare them with dose measures found in the comparison population (East Jim Thorpe).
- To determine the extent to which environmental, behavioral, occupational, socio-economic, and other factors influence exposure to cadmium and lead in the target and comparison populations.
The second part of the study to be released late in 1994 involves a set of medical test batteries, which were obtained from study participants, that assess immune, kidney, and liver function.
There are presently organized citizens groups in and around the Palmerton area. The concerns of the citizens are based on the off-site, heavy metals contamination in the environment and if people's health is being affected. An additional concern of the citizens is the possibility of on-going contamination of the community by the recycling facility presently in operation.
EPA has conducted studies indicating that the environment has been impacted by release of heavy metals. EPA has divided the site and surrounding areas into 4 Operable Units in order to efficiently address the contamination in different environmental media. After studies are completed for each Operable Unit, EPA will decide what can and will be done to clean up the contamination. EPA will share the clean-up proposals with the public to solicit comments that the people may have regarding those remediation proposals. In fact, EPA has already requested that ATSDR provide a health consultation on a proposal for clean-up levels of soil and indoor dust. That consultation appears in Appendix B. ATSDR will provide health consultations or other advice that EPA requests regarding clean-up activities for other Operable Units.
At this time, we cannot determine if exposures to contaminants in the area have caused adverse health effects to people in the community. After review of the available health outcome data, no adverse health effect could be linked to exposure to contaminants. However, because levels in the environment are high and exposure is occurring, we are concerned about possible adverse health effects. For that reason, the Biological Indicators of Exposure to Cadmium and Lead, Palmerton, Pennsylvania study was conducted. Hopefully, that study will provide more site-specific health data to help us evaluate possible health impacts.
EPA is investigating the possibility that the recycling facility presently in operation may be contributing additional contamination to the area. If EPA requests ATSDR to evaluate any information gathered at the facility, we will do so. EPA will notify the plant if violations are found and take actions to ensure the plant operates according to regulations.